The present invention relates generally to a dozer blade mounting assembly and more specifically to a mounting assembly which allows the pitch of a dozer blade to be adjusted independently of the blade tilt angle.
There are many known techniques for adjusting the pitch and tilt of a dozer blade. For example, FIG. 1 depicts a well-known technique for effecting dozer blade tilt and pitch. In FIG. 1, dozer blade 10 is supported along its back surface 12 by push beams 14, 16. Push beams 14, 16 are fastened to back surface 12 by way of pivot hinges 18, 20. Hydraulic cylinder 22 is fastened to back surface 12 of dozer blade 10 by way of joint 23 and to push beam 14 by way of joint 27. Adjustable strut 24 is fastened to back surface 12 of dozer blade 10 by joint 25 and to push beam 16 by joint 29. Adjustable strut 24 is typically comprised of a turnbuckle, jack screw or the like which can be manually adjusted to change the overall length of strut 24. Hydraulic cylinder 22 is typically attached to the appropriate hydraulic circuit (not shown) which allows the length of cylinder 22 to be adjusted from a remote position. The conventional design depicted in FIG. 1 allows the pitch angle 26 of dozer blade 10 to be adjusted by setting the appropriate length of strut 24 and adjusting cylinder 22 to a comparable length. Thus, it can be appreciated that the greater the pitch angle between vertical axis 28 and back surface 12 of dozer blade 10, the greater cylinder 22 and strut 24 must deviate from a neutral (or center) position.
To effect tilt 30 of dozer blade 10, cylinder 22 is lengthened or shortened while strut 24 maintains a fixed length. For example, if cylinder 22 is lengthened (while strut 24 remained fixed), left corner 32 of dozer blade 10 will rise while right corner 34 of dozer blade 10 will remain substantially unaltered. Similarly, if cylinder 22 is shortened (while strut 24 remains fixed), left corner 32 of dozer blade 10 will lower while right corner 34 of blade 10 will remain substantially unaltered. Thus, it will be appreciated that the conventional design depicted in FIG. 1 can be used to alter the pitch 26 and tilt 30 of dozer blade 10.
Although the conventional design depicted in FIG. 1 is desirable because of its low cost and mechanical simplicity, it is not without its drawbacks. For example, it can be seen that there is an interdependence between setting pitch 26 and tilt 30. For example, if tilt 30 of blade 10 is set to its desired angle and thereafter pitch 26 is set, initial tilt angle 30 will be effected by virtue of the above-mentioned interaction between the pitch and tilt of blade 10. This interaction necessitates several interations between tilt and pitch adjustment before tilt and pitch can be adjusted to their desired set points.
Thus, in bulldozer designs which support the bulldozer blade via two main push beams, it can be seen that conventional designs which have kept the tilt/pitch mechanisms simple have not been altogether satisfactory in providing independently controllable pitch and tilt of the dozer blade.
Accordingly, it is an object of this invention to provide a simple mechanism for controlling the pitch and tilt of a dozer blade independent of one another. It is a feature of this invention to have the dozer blade joined to a support arm by way of a cam.
It is an advantage of this invention that when the cam is rotated about its rotational axis, the pitch of the dozer blade is changed independent of the tilt angle of the dozer blade.